A downhole tool for engaging a borehole wall of a well, with outwardly displacing gripping elements to engage the borehole wall in such a way as to prevent rotation of the tool relative to the borehole wall, thereby preventing a downhole motor from imposing a reactive torque on the workstring uphole from the tool. The gripping elements can have one or more rolling elements, such as wheels, to roll longitudinally along the borehole wall in either the uphole or downhole direction, or both, while preventing transmission of reactive torque to the workstring. The gripping elements can also be configured to prevent longitudinal motion of the tool, such as blades. Displacement of the gripping elements can be hydraulically actuated.